At first we thought my be closing water is evaporating due to excessive heat and for that we minimized closing water impulse from 600 sec to 300 sec but result is same.

We have some observations as follows:

01. At the beginning of every separation cycle we do not get any symptom of fuel leaking.02. After 1000-1400 seconds separation cycle start we observe fuel leaking start and continue till end of the cycle.03. The leaking amount is not much more but it is affect our overall fuel consumption.04. Here the minimum discharge fuel pressure is 1 bar but the leaking is not affecting the line pressure as a result we are not getting any clean oil discharge alarm.05. Not found any fuel leaking through V6 valve delivery line.

01. Dismantled the complete bowl and change all sealing kits ( GEA original spare parts).02. Measured the bowl height and noted 18.5 mm( as per manual 20+/- 2mm).03. Checked the flow variation by speed up/down frequency of feed pump motor but every cases result is same.04. Cross checked all setting parameters with commissioning report and found ok.

So we are expecting your valuable suggestion to overcome the problem at earliest. Thanks in advance for your kind co operation.

We fitted the O ring in its place (groove). Actually when we noticed the problem, we overhauled the complete bowl by GEA original spare parts. The separator is running smoothly without showing any alarm. But when we inspected through sludge inspecting port after 1400 seconds we found leaking starts with droplet. We are not sure is it common phenomena for all OSE 80 models or not.

"At first we thought my be closing water is evaporating due to excessive heat and for that we minimized closing water impulse from 600 sec to 300 sec but result is same."

I do not understand this remark. If you thought that the closing water was evaporating and causing the bowl to open, why did you shorten the time water was admitted to the bowl, rather than increasing it?? Or is the time you quote the interval between closing impulses rather than the duration of them?

For many years all purifier makers have suggested purifying HFO at about 98 C so this is nothing new and does not cause a problem elsewhere.The Bowl closing water is trapped between the piston and cylinder of the bowl mechanism. The rotation of the bowl creates centrifugal force by throwing the water towards the outside (as in a pump) creating the pressure to close the bowl, because the water is under pressure its boiling point is raised over 100 C, the exact amount depending on the pressure. So I do not believe that evaporation of the operating water is a problem, I suggest you return the setting to what it is supposed to be in the maker's manual.

You say that the Separator is running as a Clarifier, this is very unusual these days. Many, many years ago it was common to put fuel through a clarifier to remove the water and then a purifier to remove the dirt. However, for the last 40 years or so the makers have preferred running the oil through 2 purifiers in series in order to get the cleanest oil. In theory you would get cleaner oil by running the two purifiers in parallel, each at 50% flow rate, but the makers experience of how badly separators are usually maintained led them to prefer two in series, as a "Belt & Braces measure".It would be worth reading the makers guidance on installation to see what they recommend for this model of purifier and how the rated output of each purifier, on the grade of fuel you are using, compares with the fuel consumption of the plant. and to see if you are supposed to be running all 3 purifiers in parallel at the minimum flow rate required to keep your clean fuel tanks full, or two of them in series with the third being on "stand By" or down for maintenance. If it is two in series should one be set up as a clarifier or both as purifiers?

You say that the sludge interval is set to 3,600 seconds, 60 minutes or 1 hour.When Purifiers were manually cleaned it was usual to stop them for cleaning every day, to manually remove all the sludge. If the oil was very dirty sometimes more frequently.The first automatically de sludging purifiers had a default sludge interval of 4 hours which was supposed to be altered in the light of experience with each batch of fuel processed, and might have to be reduced to 30 minutes if the oil was badly contaminated.Purifier designers have realised that the smaller the volume in the bowl to store the accumulated sludge, the smaller, lighter and cheaper they can make the purifier. Consequently, the sludging interval is getting shorter with each new generation of Purifier.It may well be that your sludge interval is too long, as the oil discharge starts after 1,000 seconds I would try setting the sludge interval to 1,000 seconds and see if that cures the problem. That is about 16 minutes and is not excessively short for a modern purifier and dirty oil.

When the Sensitrol / Gravitrol Seperators ( Separators that de sludged when they detected water in the clean oil outlet, rather than using a timer) were introduced they happily de sludged every hour or so in calm weather but as soon as the weather got rough and stirred up the sediment in the tanks they appeared to go crazy and were sludging every few minutes, it took a long time for everyone to realise they were working properly and sometimes they just needed to de sludge every 5 minutes.

Hope this helps you to resolve the problem.

BP

It is always better to ask a stupid question than to do a stupid thing.

Perhaps try checking the condition of the water chamber bottom which if the vanes are worn may cause a reduction to the piston pressure, as the water is not being "pumped" correctly.

Also, although you mentioned you changed all o-rings and seals, be very careful with the polyamide gasket on the annular piston. The manual should say how much it should protrude by when in place, it does take some work. Best way I found was to get some smooth copper with no burrs etc, put it in a vice, then use the vice to push the gasket in place around the whole circumference. I think the manual suggests this method, I've been on vessels where senior engineers have not liked me using this method which resulted in having to take the bowl apart 3 times until they let me do it properly.

One more thing to check is the closing water line, which if is the same as other Westfalias will also be the opening water line. Closing the bowl only takes a pulse of water, opening it takes around 5 seconds if I remember right, through the same hose. If the water line is leaking because of a fault solenoid valve it may cause the bowl to slowly open.

Since you mention changing parameters of the control system, it is possible that somebody has messed with these also which I have found in the past. Check the manual to see that nobody has increased the closing water topup pulse length, and as someone else suggested, try putting the frequency of the pulse back to original settings.

And one more thing to try, you didn't mention if you tried manually adding water to the closing chamber once the leak starts. When it happens, try giving it a split second of water just to see if it does actually stop the leak.

Opening and closing enter into the bowl via same hose. At present setting closing water pulse is 0.1 sec with 300 sec interval. That means after every 300 sec closing water enters into the bowl for 0.1 sec. I have checked by increasing the pulse length from 0.1 to 0.4 sec. Result is same.

I am worried to increase the pulse length more because excess closing water will accidentally open the bowl. As the throughput is 11 m3/h. So there will be possibility for huge oil loss.

Big Pete wrote:You say that the Separator is running as a Clarifier, this is very unusual these days. Many, many years ago it was common to put fuel through a clarifier to remove the water and then a purifier to remove the dirt. However, for the last 40 years or so the makers have preferred running the oil through 2 purifiers in series in order to get the cleanest oil. In theory you would get cleaner oil by running the two purifiers in parallel, each at 50% flow rate, but the makers experience of how badly separators are usually maintained led them to prefer two in series, as a "Belt & Braces measure".It would be worth reading the makers guidance on installation to see what they recommend for this model of purifier and how the rated output of each purifier, on the grade of fuel you are using, compares with the fuel consumption of the plant. and to see if you are supposed to be running all 3 purifiers in parallel at the minimum flow rate required to keep your clean fuel tanks full, or two of them in series with the third being on "stand By" or down for maintenance. If it is two in series should one be set up as a clarifier or both as purifiers?

BP

I've had this running through my head since you first mentioned it's running as a clarifier, and BP mentioned/covered my curiosity, but you haven't touched on a response to it.So I think it's worth noting again to see what you have to say about it.

You say that the Separator is running as a Clarifier, this is very unusual these days. Many, many years ago it was common to put fuel through a clarifier to remove the water and then a purifier to remove the dirt. However, for the last 40 years or so the makers have preferred running the oil through 2 purifiers in series in order to get the cleanest oil. In theory you would get cleaner oil by running the two purifiers in parallel, each at 50% flow rate, but the makers experience of how badly separators are usually maintained led them to prefer two in series, as a "Belt & Braces measure".It would be worth reading the makers guidance on installation to see what they recommend for this model of purifier and how the rated output of each purifier, on the grade of fuel you are using, compares with the fuel consumption of the plant. and to see if you are supposed to be running all 3 purifiers in parallel at the minimum flow rate required to keep your clean fuel tanks full, or two of them in series with the third being on "stand By" or down for maintenance. If it is two in series should one be set up as a clarifier or both as purifiers?

BP

Dear Sir,

We have 03 installations and we run twice in parallel to fulfill the plant demand. So two working and one standby mode but all in parallel. Fuel consumption of my plant is 22 cubic meter / hour. We run two purifiers at each throughput 11 cubic meter/ hr. Where the maximum capacity of each purifier is 15.4 cubic meter/hr.

We did not found any gravity disc in inlet/outlet section and the unit is working as liquid- solid separation not liquid-liquid- solid separation. That means its only removing solids from inlet oil.

We have installations of 12 LO separators (OSE 20) which works as a purifier (liquid-liquid-solid separation). And there is a gravity disc to create interface between oil and water. If incase sealing interface brakes we get "No water seal" alarm.

But we never get such alarm on HFO separators.

We know that reducing discharge interval will solve the problem but we are not getting any logic on that because at the beginning of every cycle Sludge Monitoring System (SMS) check the sludge space and if it full it will be displayed by alarm.

How does the sludge monitoring system know that the sludge space is full?Is it working, as I suggested earlier, by detecting water in the oil discharge line?

Purifiers using this system do not have Gravity discs, but as soon as the sludge space is full, water will be discharged and this should automatically start a de sludge cycle, discharging both the solids and the water, unless somebody has switched this off or it is not working!

Good Luck.B.P.

It is always better to ask a stupid question than to do a stupid thing.

How does the sludge monitoring system know that the sludge space is full?Is it working, as I suggested earlier, by detecting water in the oil discharge line?

Purifiers using this system do not have Gravity discs, but as soon as the sludge space is full, water will be discharged and this should automatically start a de sludge cycle, discharging both the solids and the water, unless somebody has switched this off or it is not working!

Good Luck.B.P.

Dear Sir,

The Unitrol device continuously monitor sludge content and water content by means of Sludge Monitoring System (SMS) and Water Monitoring System (WMS). These separators equipped with liquid sensing pump which always monitor sample line pressure. If sample line pressure is zero or less than set value it will consider bowl space has been filled with sludge and will initiate discharge.

In your last message you mention ALCAP systems. All modern Alfa Laval separators works on ALCAP principle. I am attaching a video link on how Unitortrol works on GEA separators. If you kindly manage some time to watch the video, you will get the complete picture.

At first we thought my be closing water is evaporating due to excessive heat and for that we minimized closing water impulse from 600 sec to 300 sec but result is same.

We have some observations as follows:

01. At the beginning of every separation cycle we do not get any symptom of fuel leaking.02. After 1000-1400 seconds separation cycle start we observe fuel leaking start and continue till end of the cycle.03. The leaking amount is not much more but it is affect our overall fuel consumption.04. Here the minimum discharge fuel pressure is 1 bar but the leaking is not affecting the line pressure as a result we are not getting any clean oil discharge alarm.05. Not found any fuel leaking through V6 valve delivery line.

Did you find any solution of thos problem allready or not? Because on our ship I have the same problem like you. So if u allready eliminate problem let me to know how. Thank in advance.

Sorry to say that we have tried to solve by all possible ways. But problem is still on. As an alternating solution we are collecting sludge and leakage oil in a tank and trying to recover oil by gravity separation and again sending to the separator for further treatment.

How do you draw the oil from the sludge tank?Do you manually drain the water from the bottom of the sludge tank and let the oil overflow into another tank and pump it from there to the service tank?It would be possible to fit a capacitance probe, as used in Oily Water Separators, (available on-line from RS Components, into the side of the tank, to operate a solenoid valve on the water drain line automatically when the water level reaches a certain height inside the sludge tank, that would ensure that most of the heavy phase,( water & Solids)would be dumped and only relatively clean oil would overflow to be pumped back into the settling tank.I sailed on a ship where they had a similar problem with the L.O. purifier and the Chief ordered that the sludge tank be purified back into the engine sump, the purifier couldn't deal with the % of water and solids in the sludge tank and most of it passed straight through, into the sump and emulsified the entire oil charge.I thought you said earlier that you had resolved the problem by shortening the de sludge interval?

Good LuckBP

It is always better to ask a stupid question than to do a stupid thing.